Montana Audubon

Montana Audubon works at the local, state and national policy levels to protect our natural heritage.

The Exotic House Sparrow

Posted on January 1, 2014

By David Cronenwett

I carried a load of garbage to the back ally this morning, surprising a flock of about thirty small birds hunkered down in the shrubs near the trash bin. Standing there in my pajamas and slippers in the snow, I wince at the little monsters with a well-honed repulsion; they barely react, just stirring a bit with a collective flutter of wings, casually adjusting themselves to my presence. The rodent-like chirp that echoes through the horde identifies them as House Sparrows (Passer domesticus).That these birds regularly park themselves right next to the trash receptacle is beyond coincidence and seems entirely appropriate. I slam the trashcan lid as hard as I can, sending the birds, temporarily, to a clump of bushes twenty feet away. House Sparrows are strongly associated with human civilization, probably benefitting from the proliferation of our species since the dawn of agriculture.

Along with the Rock Dove (pigeon) and European Starling, House Sparrows (sometimes lovingly called Flying Rats) are some of the most abundant and commonly observed birds in urban and suburban habitats. The history of how this species became established in North America is an instructive one that illustrates a strain of ecological ignorance that persists to this day. In mid-nineteenth century New York City, a movement arose among wealthy “naturalists” to introduce European species to the continent. Reasons for this were largely cultural; the mission of the American Acclimatization Society for example, was to introduce “such foreign varieties of the animal and vegetable kingdom as may be useful or interesting.” Many well-to-do families of the time still had strong connections and memories of western Europe which was considered the pinnacle of civilization and culture. It became something of a noble pastime in those days for the wealthy to bring a little bit of Europe to America in the form of birds, mammals and plants. However, the effects of importing such “useful or interesting” creatures from the Old World, intentionally or otherwise, have been profound and lasting.

In 1851, House Sparrows were released in NYC parks. By the turn of the twentieth-century, they could be observed in the Rocky Mountain States. Today, they appear on every continent except Antarctica. From Tierra del Fuego to the Northwest Territory, these animals have proven to be extremely well adapted to coexisting with people across the Americas and elsewhere. They are a highly gregarious bird with a social structure similar to barnyard chickens; older, more dominant males have larger black “bibs” which communicates their higher standing to other males, thus preventing energy-intensive skirmishes. Their lack of fear towards humans, preference for nesting in manmade structures and generalist diet (seeds, insects, garbage) make them a supreme competitor with native birds…and herein lies the problem.

When introduced species begin to negatively impact biodiversity, ecosystems can unravel. Some Eurasian introductions, like Pheasants, are pretty innocuous and considered functionally native in many areas. Spotted Knapweed and Starlings though are another story, in many cases completely displacing native organisms that have not evolved to compete with them. With House Sparrows, the biggest offense is nesting cavities; they will actively kill the eggs and young of native birds (bluebirds, tree swallows, etc.) in nesting sites wherever they find them. (They are also known to kill adults inside nest boxes on occasion.) At feeders, large flocks of Sparrows will sometimes run native birds out of the area with their aggressive presence. In urban, suburban and wildland-urban interface areas where House Sparrows flourish, the effects on native birds can be significant. The problem of invasive species is one of the greatest threats to ecosystems worldwide and the cute little House Sparrow pestering you for a handout at the outdoor cafe, stands as an important reminder of this!

Although not the worst noxious creature in Montana, combined with the deleterious impacts of habitat loss, climate change and other introduced species, House Sparrows do suppress some native bird populations.

Bluebird lovers, of whom there are many in our state, should not hold the House Sparrow in high regard. The most effective management for Sparrows is by lethal methods; since they are considered a pest species, House Sparrows are not covered by the Migratory Bird Act or other laws. While this may be distasteful to some, more passive means of keeping Sparrows at bay have limited effectiveness, whereas destroying them outright can improve nesting success for natives like Mountain Bluebirds almost immediately. When introduced species become “noxious,” native wildlife and habitat that we love can disappear for good. Whether the organism in question arrived here on accident or intentionally, we are ultimately responsible for the aftermath. Though the problem of invasive species can be challenging, we owe it to the natives to create circumstances that favor their continued presence on the landscape.

I’m still staring down that flock of House Sparrows, wondering if, over time, they will naturalize to this place as just another ecological player, along with the chickadees, nuthatches and brown creepers. Meanwhile, in the morning haze of my mind I imagine more creative solutions to the House Sparrow menace…such as using them as a source of biofuel, creating a Sparrow-based millenary industry on par with the extinction inducing one of the last century or trying to establish a taste for their tender flesh in high-end bistros. Just as I think I hear “sir, would you like a side of Sparrow with that?”, the wind picks up, sending this pajama-clad madman inside. And as predicted, the flock of House Sparrows quickly return to their roost near the garbage